As devices relying upon integrated circuits (ICs) have increased in complexity and functionality, those devices have required ever more dynamic ICs to meet the demands of those device users. Polysilicon resistors have been used in many IC structures to provide effective resistance function at lower cost than conventional resistor structures. However, polysilicon resistors may have a high sheet resistance, and joule heating of these resistors can negatively impact circuit performance and increase the chances of metal electro-migration wear-out.
Conventional approaches to reduce joule heating in polysilicon resistors include optimizing placement of through-silicon-vias (TSVs) and circuit floor planning to reduce heating effects in the circuit. However, TSVs have inherent trade-offs, for example, they increase the complexity of circuit formation and processing, and also increase costs.
Other conventional approaches include using micro-channels for liquid cooling. These micro-channels provide a conduit for cooling fluid to reduce heating in the resistor structure. However, micro-channels also suffer from drawbacks, for example, they can be unreliable (e.g., due to leakage), increase processing and fabrication costs and complexity, and may be difficult to calibrate precisely.